Purpose:To investigate the utility of functional and morphological magnetic resonance imaging (MRI) to assess the extent of brain injury in a hypoxia-ischemia (HI) piglet model and further to validate that the desired ischemic injury was successfully induced. Materials and Methods:MRI was performed at 1.5 T in anesthetized piglets (N ϭ 10, age ϭ 12-36 hours). Relative cerebral blood flow (rCBF), time-to-peak (TTP) contrast, and apparent diffusion coefficient (ADC) were estimated at different time points pre-, during, and post-HI. The effect following bilateral clamping of the carotid arteries was assessed by contrast-enhanced MR angiography (MRA) and phase contrast MR angiography (PCA) (N ϭ 4). Results:A linear correlation was observed between relative cerebral perfusion reduction and cerebral ADC during HI (r 2 ϭ 0.85, P Ͻ 0.05). There was no correlation between rCBF reduction during 30 minutes of HI and cerebral ADC after 30 or 150 minutes of reperfusion/reoxygenation (RR). Conclusion:The combination of morphological and functional (perfusion and diffusion) MRI enabled consistent assessment of both the presence and absence of complete occlusion as well as the functional significance of the occlusion. WITH THE ADVANCES IN REPRODUCTIVE and neonatal intensive care, clinicians are now confronted with an increasing number of surviving high-risk newborns that suffer from considerable neurologic morbidity that is often associated with lifelong handicaps (1). New diagnostic tools are therefore needed to detect early brain injury and monitor interventions aimed at minimizing or preventing irreversible brain injury. Magnetic resonance imaging (MRI) is an attractive diagnostic modality in the developing brain because of the high contrast resolution of this technique combined with its relative noninvasiveness (2). MR perfusion and diffusion imaging have proved to be sensitive tools for early detection of brain injury (3-5).The piglet model is commonly used in medical research, due to its similarities to the human brain (6). Studies have shown that the gray/white matter distribution, changes in brain morphology during development, and sequence of nervous system maturational changes are comparable for pigs and humans. Also, the overall shape and gyral pattern of the piglet brain are similar to those of the human's (7,8).The availability of a well-controlled piglet model is of great importance for many types of studies aimed at investigating neonatal injury due to hypoxia-ischemia (HI). Such a model requires a sensitive method to assess the degree of functional changes caused by the induction of HI. Another important aspect is to have a sensitive imaging method to validate that total carotid occlusion has indeed been achieved. This was performed by MR angiography (MRA). Such a combined functional (perfusion and diffusion) and morphological (tissue and vessel anatomy) assessment can now be provided by MRI using novel imaging methods combined with new MR contrast agents. In the current study, we have utilized an intravascular ...
Occasionally, an obstetrician can experience conflicts between the mother and her fetus. In a situation where the life of the fetus is in danger, religious, cultural, or other convictions may cause the mother to refuse the physician's recommendations for delivery. When there is a medical indication to perform cesarean section, but the mother refuses, has the obstetrician then a right to perform a cesarean section to save the fetus from possible death or serious injury? In 1987, The Norwegian Directorate of Health made a statement on cesarean section without consent, but later, new legislation on patient rights has been introduced. In Norway, no scientific medical articles have been published on this topic, and no cases have yet been brought to court. Cases of court‐ordered cesarean section have been reported from the UK and the USA. In this report, we discuss some of the ethical, moral, and legal aspects of forced cesarean sections.
Objective: Previous animal studies indicated that interleukin (IL)-10 attenuates the inflammatory response to a challenge by inflammation and hypoxia-ischemia, but the effect of IL-10 administration after onset of inflammation has not been studied. We wanted to assess (1) whether IL-10 had a beneficial effect on brain metabolism and microcirculation in newborn piglets after an inflammatory, hypoxic and ischemic challenge, and (2) whether IL-10 had any harmful effects per se. Methods: Anesthetized piglets were randomized to control (n = 8), IL-10 (n = 10), endotoxin (ETX) (n = 10), or ETX and IL-10 (ETX/IL-10) (n = 10) groups. IL-10 was administered after pretreatment with saline in the IL-10 group or ETX in the ETX/IL-10 group. Then, cerebral hypoxia and ischemia was induced by bilateral clamping of the common carotid arteries and ventilation with 8% O2 for 30 min, followed by 4 h of reoxygenation and reperfusion. Extracellular levels of lactate, pyruvate, and glycerol were measured with microdialysis in periventricular white matter and parasagittal subcortical tissue, and tissue oxygenation and microcirculation were measured with Doppler technique. We compared the areas under the concentration-time and flow-time curves and maximum concentrations between (1) the ETX/IL-10 and ETX groups, and (2) the control and IL-10 groups. Results: We found no differences between (1) the ETX/IL-10 and ETX groups, and also no differences between (2) the control and IL-10 groups. Conclusion: We could not show that the treatment with IL-10 after onset of inflammation had neuroprotective effects in the newborn piglet brain. IL-10 did not attenuate metabolism in the absence of ETX-induced inflammation.
In this Göttingen minipig model, a species closer to humans than animals commonly used in experimental studies of perinatal brain injuries, intrauterine asphyxia following pretreatment with saline caused brain stem and white matter injury. This model can be further developed to study the impact of other intrauterine exposures on brain injury.
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